Plug-valve.



No. 745,316. PATBNTED 1130.1,1903.

R. C. BLAKE;

PLUG VALVE." uruouxon FILED SEPT. 29, 1902. no MODEL.

Fig.1

mfnesses I III/$6722??? M0 i iwy Patented December 1, 1903.

PATENT OFFICE.

RICHARD C. BLAKE, OF CINCINNATI, OHIO.

PLUG-VALVE.

' SPECIFICATION forming part of Letters Patent No. 745,316, dated December 1903' Application filed September 29, 1902. Serial No. 125,189.

(No model.)

To all whom it may concern.-

Be it known that I, RICHARD C. BLAKE, a citizen of the United States of America, and a resident of Cincinnati, county of Hamilton, State of Ohio, have invented certain new and useful Improvements in Plug-Valves,of which the following is a specification.

The object of my invention is a plug-valve which is held to its seat with a pressure which prevents leakage, but which does not create any binding effect and which cannot be regulated by an unskilled person so as to create such an effect and in which the pressure in the chambers at the ends of, the valve due to the expansion of heated air therein is re-, leased. This object is attained by the means described in the specification and illustrated in the accompanying drawings, in which- Figure 1 is a view of a plug-valve embodying my invention, showing the valve-casing in central section and the plug-valve, valvestem, and handle in elevation. Fig. 2 is asectional view of the same, taken upon line as w of Fig. 1, the valve-stem being shown broken off. Fig. 3 is a detailview in elevation of the valve and valve-stem.

Referring to the parts, valve-casing A has a straight channel a passing through it, through which the fluid to be regulated is to pass. Crossing channel a is a tapered bore a, which upon one end is closed by a wall a and upon the open end has an ext eriorly-screw-threaded extension a, which receives a cap a Plugvalve B is tapered similarly to bore a and is seated therein across channel a, leaving a chamber 0, between its end and the wall a Upon its opposite end the valve B is reduced, forming a shoulder 19 and a valve-stem Z), which projects out through cap a and upon its end receives a valve. Shoulder b has an annular groove 12 cut into it, from which a channel 1) extends through the plug-valve to its opposite side. Upon shoulder 12 is seated a washer C, in which is a perforation c. Surrounding valve-stem 1), between washer C and the cap a is a coiled spring D, which holds the plug-valve to its seat.

handle 19* for turning the It is seen that with my construction the valve is held yieldingly to its seat by the spring D, so that it cannot become wedged into the seat so as to become stiff in action, as is the case with plug-valves which project through the valve-casing and upon their ends receive nuts to hold them in place. It is seen, likewise, that an unskilled person could not grind this valve so tightly to its seat that it would become bound, since the pressure with which it may be pushed to its seat is limited by the pressure which can be brought upon spring D, which cannot be increased after cap a is seated against the end of extension a The channel b puts chamber a in communication with the chamber surrounding the valve-stem, which itself is in communication with the air, since cap a has no paclc ing surrounding the valve-stem. hen the air in chamber becomes expanded by reason of heat, it does not push the valve away from its seat, but is released through channel b into groove 11 and thence out through perforation c in the washer into the chamber surrounding the valve-stem.

That I claim is 1. The combination of a casing, a fluidchannel therethrough, a plug-valve crossing the channel forming chambers at the ends of the valve and having a channel passing through it and putting the chambers in communication with each other and a vent in the walls of one of the chambers substantially as shown and described.

2. The combination of a casing having a fluid-channel therethrough, a tapered bore crossing the channel from one side of the easing having one end of the bore closed, atapered plug-valve to fit the bore leaving a chamber at the closed end of the bore and having a channel passing through the valve into the chamber, a means for venting the other end of the bore and a means for holding the plug yieldingly to its seat substantially as shown and described.

3. In a plug-valve the combination of a casing having a channel therethrough, a tapered bore transverse to the channel having one of its ends closed, a tapered plugvalve seated Within the bore forming a closed ehznnber at one end and having a channel passing longitudinally therethrough, a cap surrounding the stem of the Valve forming a chamber about it, the air, and aspi'i which communicates with 11g between the cap and the I valve to hold the same yieldingiy to its seat substantially as shown and described.

RICHARD O. BLAKE. Witnesses M. J. SOANLAN, XV. F. MURRAY. 

